Trail Making Test
The Trail Making Test is a neuropsychological test of visual attention and task switching. It consists of two parts in which the subject is instructed to connect a set of 25 dots as fast as possible while still maintaining accuracy. It can provide information about visual search speed, scanning, speed of processing, mental flexibility, as well as executive functioning. It is also sensitive to detecting several cognitive impairments such as Alzheimer's disease and dementia. History The test was used in 1944 for assessing general intelligence (and was part of the Army Individual Test of General Ability). Starting in the 1950sR. M. Reitan, R. M. (1955). The relation of the trail making test to organic brain damage. Journal of Consulting Psychology Reitan R. M. (1958). Validity of the Trail Making test as an indicator of organic brain damage. Percept. Mot Skills, 8, 271-276. researchers began using the test to assess cognitive dysfunction stemming from brain damage, and it has since been incorporated into the Halsted-Reitan battery. The Trail Making Test is now commonly used as a diagnostic tool in clinical settings. Poor performance is known to be associated with many types of brain impairment; in particular frontal lobe lesion. Method and Interpretation The task requires a subject to 'connect-the-dots' of 25 consecutive targets on a sheet of paper or computer screen. There are two parts to the test: A, in which the targets are all numbers (1,2,3, etc.)and the test taker needs to connect them in sequential order, and B, in which the subject alternates between numbers and letters (1, A, 2, B, etc.). If the subject makes an error, the test administrator is to correct them before the subject moves on to the next dot. The goal of the test is for the subject is to finish the part A and part B as quickly as possible, the time taken to complete the test is used as the primary performance metric. Error rate is not recorded in the paper and pencil version of the test, however, it is assumed that if errors are made it will be reflected in the completion time. Test B, in which the subject alternates between numbers and letters, is used to examine executive functioning. Part A is used primarily to examine cognitive processing speed. Part B differs from Part A specifically in that it assesses more complex factors of motor control and perception Arbuthnott, K., Frank, J. (2000). Trail making test, part B as a measure of executive control: validation using a set-switching paradigm. Journal of Clinical and Experimental Neuropsychology. 22(4); 518-528. Part B of the Trail-Making test consists of multiple circles containing letters (A-J) and numbers (1-13). The participant’s objective for this test is to connect the circles in order, alternating between number and letter (e.g. 1-A-2-B) from start to finish Gaudino, E., Geisler, M., Squires, N. (1995). Construct validity in the trail making test: What makes part B harder? Journal of Clinical and Experimental Neuropsychology. 17(4); 529-535. The participant is required not to lift their pencil from the page. The task is also timed as a means of assessing speed of processing Conn, H. (1977). Trail-making and number-connection tests in the assessment of mental state in portal systemic encephalopathy. Digestive Diseases. 22(6); 541-550 . Set-switching tasks in Part B have low motor and perceptual selection demands, and therefore provide a clearer index of executive function . Throughout this task, some of the executive function skills that are being measured include impulsivity, visual attention and motor speed . References Further reading *Corrigan, J. D., Hinkeldey, M. S. (1987). Relationships between parts A and B of the Trail Making Test. J. Clin Psychol, 43 (4), 402–409. *Gaudino, E. A., Geisler, M. W., Squires, N. K. (1995). Construct validity in the Trail Making Test: What makes Part B harder? J Clin Exp Neuropsychol, 17 (4), 529-535. The Trail-Making test is a measure of executive dysfunction. External links *PEBL Test Battery A free computer-based research-oriented implementation of the trail-making test is available as part of the PEBL Project Category:Neuropsychological tests Category:Cognitive tests